SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edf020a7846ed8b0ff2aca223da250f526c6b0e6bed738271a1eecca9c680bbc' 
  AND token = 'hCGYxvRA4MljNpQ1nzJ1LwlBRC3gM5tQLFqOgL7v+Ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}